WristDelta

WristDelta is a focused accuracy tracker for mechanical, quartz, and solar watches. Add a watch, compare it with iPhone System Time, and record how far ahead or behind it is. Take another reading hours or days later and WristDelta calculates the watch’s real-world rate in seconds gained or lost per day. QUICK, CLEAR MEASUREMENTS - Record an ahead, behind, or exact offset in seconds - Use Tap at 12 for a more precise seconds-hand capture - See interval and overall timing-run rates - Get clear guidance when a measurement interval is short BUILT FOR REAL WATCH USE - Keep separate timing runs after a watch is adjusted, reset, or serviced - Compare results with editable reference ranges - Add wrist, dial, crown, winder, and mixed-use conditions - Explore duration-weighted condition insights - Export your complete history to CSV PRIVATE AND OFFLINE Your watch profiles, photos, runs, and readings stay on your device. WristDelta has no accounts, analytics, advertising, or backend service. WRISTDELTA PRO — ONE-TIME LIFETIME UNLOCK The free app includes every feature and one watch. WristDelta Pro unlocks an unlimited watch collection with a one-time lifetime purchase. Price is displayed in your local App Store storefront before purchase. WristDelta uses iPhone System Time as its reference. For best results, enable Set Automatically under iPhone Settings → General → Date & Time. WristDelta measures real-world gain or loss over time. It does not replace a professional acoustic timegrapher or watchmaker inspection.